Liquid Composite Molding (LCM) processes, such as Resin Transfer Molding (RTM) and Structural Reaction Injection Molding (SRIM), are manufacturing methods for fabricating high-strength, high-volume composite parts. Composite parts are still generally cured in autoclaves, ovens, or presses using empirically based xe2x80x9crecipexe2x80x9d cures. Most previous attempts to solve the problems inherent in recipe cures have concentrated on reducing batch-to-batch variations in raw materials and pre-production xe2x80x9cproofxe2x80x9d processing to accommodate those variations. This approach has been only moderately successful, and not optimally cost effective. Current studies of multi-regional flow in LCM processes do not determine actual flow front location using real-time sensor data during the process. These studies simulate the resin flow using material and process parameters, including permeability, injection pressure, vacuum pressure, and port and vent locations. They often record the resin flow on the surface of the composite on video to compare to simulations.
The present invention accurately determines the actual flow area and location of the flow front in a short time relative to the speed of the flow front. It is not a simulation of the flow using material and process parameters before actual fabrication. Thus, the actual state of fill of the composite in relation to the ports and vents in the mold cavity is known throughout the fabrication process. The present invention can also determine flow front velocity. Since location, speed, and direction fully describe flow in the immediate future, the present invention can be used as the basis of a control methodology capable of modifying the actual condition of the material in real-time or near real-time as it is being processed. Intelligent process control would respond relatively quickly to analysis results to modify flow parameters, e.g., port injection pressure, activation/shut off of injectors, etc.
Accordingly, it is an object of the present invention to provide an apparatus and associated methodology to monitor and display the resin flow during fabrication of organic matrix composite laminates.
The foregoing object is achieved by integration of novel sensor technology, network-based data acquisition, fast finite element based reconstruction (smoothing) and contouring algorithms, and scientific visualization tools. The invention uses a robust combination of data analysis and data visualization techniques to accurately show the entire composite laminate and the flow in the laminate in an easily understood three dimensional display. The invention can display the flow area or the flow front. Either mode of display is easily interpretable without requiring any detailed knowledge of the acquisition, reconstruction, and visualization methodology.